Tracheal intubation of morbidly obese patients:: a randomized trial comparing performance of Macintosh and Airtraq™ laryngoscopes

Background. The Airtraq(TM) laryngoscope is designed to allow visualization of the glottis without alignment of the oral, pharyngeal, and laryngeal axes. We hypothesized that this new airway device would facilitate tracheal intubation of morbidly obese patients. We compared tracheal intubation performance of standard Macintosh laryngoscope with the Airtraq(TM) laryngoscope in morbidly obese patients. Methods. One hundred and six consecutive ASA I-III morbidly obese patients undergoing surgery were randomized to intubation with the Macintosh laryngoscope or the Airtraq(TM) laryngoscope. Induction of anaesthesia was standardized. If tracheal intubation failed within 120 s with the Macintosh or Airtraq(TM) , laryngoscopes were switched. Success rate, SpO(2), duration of tracheal intubation, and quality of airway management were evaluated and compared between the groups. Results. Preoperative characteristics of the patients were similar in both groups. In the Airtraq(TM) group, tracheal intubation was successfully carried out in all patients within 120 s. In the Macintosh laryngoscope group, six patients required intubation with the Airtraq(TM) laryngoscope. The mean (SD) time taken for tracheal intubation was 24 (16) and 56 (23) s, respectively, with the Airtraq(TM) and Macintosh laryngoscopes, (P < 0.001). SpO(2) was better maintained in the Airtraq(TM) group than in the Macintosh laryngoscope group with one and nine patients, respectively, demonstrating drops of SpO(2) to 92% or less (P < 0.05). Conclusions. In this study, the Airtraq(TM) laryngoscope shortened the duration of tracheal intubation and prevented reductions in arterial oxygen saturation in morbidly obese patients.